1. Field
The invention relates to a method for producing .alpha..sub.1L -adrenoceptor antagonists and to intermediates involved in this process.
2. Description
The .alpha..sub.1L -adrenoceptor antagonist having the formula: ##STR2## wherein R is hydro, methyl, or fluoro, is beneficial in the treatment of benign prostatic hyperplasia. .alpha..sub.1L -Adrenoceptorantagonists as a group are known to selectively reduce .alpha..sub.1L -adrenoceptor hyperactivity in prostatic and/or lower urinary tract smooth muscle, without significantly affecting blood pressure or causing postural hypotension. Compounds encompassing the compound of Formula, I and a method for their manufacture, are described in European Patent Publication No. 0 748 800, published Dec. 18, 1996. The present invention provides an economical alternative process for manufacturing this .alpha..sub.1L -adrenoceptor antagonist.